In the testing and servicing of air conditioning systems, it has been conventional practice to thread the equipment onto a nipple of the air conditioning system housing a Schrader valve or a similar type valve which is actuated by depression of a needle. During the attachment of this equipment to the valve, the needle is depressed and some of the refrigerant fluid escapes from the air conditioning system and is lost in the atmosphere. Additionally, the escaping refrigerant fluid comes in contact with the hands of the person attaching the equipment to the system causing a burning of the skin on the fingers. Consequently, when this operation must be repeated frequently, hands become sore with the possibility of permanent injury.
This problem is recognized in U.S. Pat. No. 3,645,496 granted Feb. 29, 1972 to Clarence G. Rawlins who developed a device for servicing refrigerator systems to prevent refrigerant fluid from escaping while testing or servicing such equipment. The Rawlins device is a T-shaped coupling, the central leg of which is connected to testing equipment or refrigeration fluid supply means. One end of the cross member of the T-shaped coupling is engaged with a valved access nipple, and the other end of the cross shaped member has a movable shaft extending therethrough for actuating the valve at the opposite end thereof.